Obama thanks staffers at last inaugural ball

1/22/13 10:10 PM EST

President Barack Obama thanked thousands of staffers Tuesday night and said they have come to represent his "deepest hopes for America."

“My main job here tonight is really simple: It’s just to say thank you," he told the crowd of between 10,000 and 15,000 at the last inaugural ball. "All of you have come to represent for me and Michelle our deepest hopes for America."

Workers from the White House, administration, DNC, campaign, and inauguration were invited to the ball at the Washington Convention Center, where Tony Bennett and Lady Gaga were slated to perform.

"The average age here is probably around 20 something. And that’s only because I’m here, which brings the average age up, quite a bit," Obama joked, according to a pool report.

He told attendees that they were more capable, serious and poised than he was at their age. “It makes me know that America’s future is in good hands," he said. "As long as all of you understand the immense and incredible power that you possess when you work together, when you join voices.”

When Obama talked about the upcoming entertainment -- a “couple of people who are pretty good musicians” -- first lady Michelle Obama did a little dance with her arms.

“It’s been a long weekend,” the president teased, according to the pool report. “She’s getting a little silly now.”

Correction: An earlier version of this post misstated the day of the ball.